The CFAR Molecular Core will provide CFAR investigators with the molecular biological regents and tools necessary to pursue their research by serving as a repository for expression vectors, antibodies and antisera, cell lines, and viral vectors. In addition to its role as a reagent repository, the Molecular Core will provide advice and expertise to investigators on such topics as the cloning and manipulation of genes and the functional analysis of viral proteins such as Env. Importantly, the Molecular Core will interface closely with the Virology Core. Viral genes will be isolated from primary viruses that are of interest to CFAR investigators and that are provided by the Virology Core, and placed into appropriate vectors. High level expression vectors will then be provided, when requested, to the Structural Core for large-scale production of gene products. The Molecular Core will also interact directly with the Clinical Core by genotyping patient samples for polymorphisms associated with altered disease progression. Thus, by consolidating and making available important reagents, by providing technical advance, by genotyping patient samples, and though the construction of expression systems the Molecular Core will facilitate interactions between the Virology, Clinical, and Structural Cores and will assist investigators in their research efforts. In addition, the Molecular Core will help foster collaborations and help draw new and established investigators into HIV/SIV research.